EMBOLIC DEVICE WITH IMPROVED NECK COVERAGE
In various aspects, the invention relates to an embolic device for treating aneurysms or other vascular disorders that exhibits improved filling and/or neck blockage over conventional devices. As one example, the embolic device can include a structure that is wound into a spiral shape. In some cases, the spirally wound embolic device includes alternating narrow portions and link portions. As another example, the embolic device can be formed from a structure wound to form an infinity shape or, in some cases, multiple infinity shapes. In instances with multiple infinity shapes, the infinity shapes can be arranged either parallel or perpendicular to each other. In certain aspects, the embolic device can include two different embolic devices that are attached by an interconnect element, such that the two devices are attached but have independent freedom of motion when placed within a vascular disorder.
This application claims priority to and the benefit of, and incorporates herein by reference in its entirety, U.S. Provisional Patent Application No. 62/652,441, which was filed on Apr. 4, 2018.
TECHNICAL FIELDIn general, various embodiments of this invention relate to embolic devices for use in the minimally-invasive treatment of aneurysms and other vascular disorders and, more specifically, to an embolic device that can be shaped and/or configured to accomplish improved filling and/or coverage of a neck of a vascular disorder.
BACKGROUNDIn general, an aneurysm is a swelling or bulge that forms a cavity in the wall of a blood vessel. One type of aneurysm is a cerebral aneurysm, which forms in an artery of the brain. A cerebral aneurysm may develop suddenly without initial symptoms, and can cause extreme pain. In general, in 15% of cerebral aneurysm cases, the patient dies suddenly upon development of the cerebral aneurysm; in another 15% of cerebral aneurysm cases, the patient dies under medical treatment; and in 30% of cerebral aneurysm cases, the patient survives after treatment but feels an acute aftereffect. As such, a cerebral aneurysm (or any aneurysm) is a very concerning development.
The treatment of aneurysms and other similar vascular disorders often involves the placement of microcoils within the cavity formed by the aneurysm or disorder. Doing so can cause blood to clot, prevent an additional inflow of blood, and decrease the risk of the aneurysm or disorder rupturing (i.e., an embolization). In order to be effective, an embolic microcoil must apply pressure sufficient to prevent additional inflow of blood, but not an excessive amount of pressure that causes rupture.
An important feature of an embolic device is its ability to block the aneurysm's neck, i.e., the opening where the aneurysm meets the blood vessel. Such blockage can be critical for ensuring that excessive amounts of blood do not flow into the aneurysm, risking further bulging or rupture. Prior approaches for blocking the aneurysm neck include covering the neck with stent-like or braided structures. While these approaches can sometimes be effective, there are still opportunities for improvement.
Accordingly, there is a need for an improved embolic device that achieves improved filling and/or blockage of a neck of an aneurysm.
SUMMARY OF THE INVENTIONIn various embodiments, the present invention relates to an improved embolic device that achieves improved filling and neck blockage over conventional devices. In particular, the device can be formed into inventive shapes that have been observed to improve neck blockage. Exemplary shapes include spiral shapes and infinity shapes, as described in greater detail below.
In addition, one factor that has been discovered to contribute significantly to unsatisfactory neck blockage in conventional devices is that the portion of the embolic device placed within the aneurysm often shifts or moves while it finds equilibrium within the aneurysm. This can take place, for example, when the aneurysm has a complex shape (e.g., bifurcated, bilobed, etc.) and the portion of the embolic device within the aneurysm expands in order to contact portions of the interior surface of the aneurysm. Movement of the portion of the device within the aneurysm can cause associated shifts/movement of the portion of the embolic device blocking the neck, which can compromise the blockage. As such, in some aspects, the invention described herein includes an embolic device that includes two treatment elements: one for placement in the aneurysm and the other for blockage of the neck. The two treatment elements can be attached with an interconnect element that allows the treatment elements to have independent freedom of motion when delivered to the aneurysm.
In general, in one aspect, embodiments of the invention feature an embolic device for use in treating a vascular disorder. The embolic device can include a flexible structure that includes a series of alternating narrow portions and link portions, each link portion circumscribing an opening in at least one plane. The structure can be adapted to form a spiral shape when unconstrained.
In various embodiments, the structure can include a coil, a flat sheet, a thin film, and/or combinations thereof. The structure can include a material including platinum, nitinol, alloys thereof, and/or combinations thereof. In some cases, the structure includes a thickness in a range from 0.0005 inches to 0.027 inches. In some cases, each narrow portion includes a helically wound coil and each link portion includes a flat sheet and/or a thin film. At least a portion of the embolic device can be radiopaque. Each narrow portion can be fixedly attached to proximate link portions. In some cases, the embolic device can include a strain relief element (e.g, a melted suture material, melted polymer, etc.) between each narrow portion and the proximate link portions. In some cases, each link portion includes a diamond-like shape.
In various embodiments, each link portion is adapted to compress when the embolic device is disposed within a microcatheter. Each link portion can be further adapted to expand upon deployment of the embolic device from the microcatheter. In some cases, the narrow portions and the link portions alternate with consistent spacing. In other cases, the narrow portions and the link portion alternate with inconsistent spacing. The embolic device can include a cover element disposed over the structure. The embolic device can include an interconnect element disposed at an end of the embolic device for attaching the embolic device to one or more different embolic devices (e.g., in series).
In general, in another aspect, embodiments of the invention feature another embolic device for use in treating a vascular disorder. The embolic device can include a flexible structure adapted to form at least one infinity shape portion when unconstrained. The infinity shape portion can include two adjacent loops crossing at a single point.
In various embodiments, the structure includes a coil, a flat sheet, a thin film, and/or combinations thereof. The structure can include a material that includes platinum, nitinol, alloys thereof, and/or combinations thereof. In some instances, the structure includes a thickness in a range from 0.0005 inches to 0.027 inches. In some cases, the flexible structure forms at least two infinity shape portions. At least two of the infinity shape portions can be arranged to align with and overlay each other and/or at least two infinity shape portions can be arranged circumferentially about an interior of the vascular disorder. At least one infinity shape portion can be rotated to be perpendicular to another infinity shape portion. The embolic device can include a cover element disposed over the structure. The embolic device can include an interconnect element disposed at an end of the embolic device for attaching the embolic device to one or more different embolic devices (e.g., in series).
In general, in yet another aspect, embodiments of the invention feature a multi-stage embolic device for use in treating a vascular disorder. The multi-stage embolic device can include a first embolic device, a second embolic device different from the first embolic device, and an interconnect element joining the first and second embolic devices and permitting independent freedom of motion between the first and second embolic devices while remaining joined together.
In various embodiments, the first embolic device includes a framing device and the second embolic device includes a filling device. In some cases, upon deployment of the multi-stage embolic device to the vascular disorder, the first embolic device is adapted to block a neck of the vascular disorder and the second embolic device is adapted to occupy an interior of the vascular disorder. The first and/or second embolic devices can include a coil, a flat sheet, a thin film, and/or combinations thereof. The first and/or second embolic devices can include platinum, nitinol, alloys thereof, and/or combinations thereof. In some instances, the first and/or second embolic devices include a thickness in a range from 0.0005 inches to 0.027 inches. In some cases, the first and/or second embolic devices are adapted to form a spiral shape when unconstrained. The interconnect element can include linked loops and/or a nitinol coil. The multi-stage embolic device can further include at least one additional embolic device different from each of the first and second embolic devices, and at least one additional interconnect element directly and/or indirectly joining the second and additional embolic device(s). The additional interconnect element(s) permit independent freedom of motion between the second and additional embolic device(s) while remaining joined together. The multi-stage embolic device can include a cover element disposed over the first and/or second embolic devices.
In general, in still another aspect, embodiments of the invention feature a method for treating a vascular disorder. The method can include the step of delivering a multi-stage embolic device to the vascular disorder. The multi-stage embolic device may include a first embolic device, a second embolic device different from the first embolic device, and an interconnect element joining the first and second embolic devices and permitting independent freedom of motion between the first and second embolic devices while remaining joined together. The method can further include disposing the second embolic device within an interior of the vascular disorder, and disposing the first embolic device to block a neck of the vascular disorder.
In various embodiments, one of the first and second embolic devices includes a framing device and the other embolic device includes a filling device. The first and/or second embolic devices can include a coil, a flat sheet, a thin film, and/or combinations thereof. The first and/or second embolic devices can include platinum, nitinol, alloys thereof, and/or combinations thereof. In some instances, the first and/or second embolic devices include a thickness in a range from 0.0005 inches to 0.027 inches. In some cases, the first and/or second embolic devices form a spiral shape when unconstrained. The interconnect element can include linked loops and/or a nitinol coil. The multi-stage embolic device can further include at least one additional embolic device different from each of the first and second embolic devices, and at least one additional interconnect element directly and/or indirectly joining the second and additional embolic devices. The additional interconnect element(s) permit independent freedom of motion between the second and additional embolic devices while remaining joined together, and the method can further include disposing the additional embolic device(s) within the interior of the vascular disorder. The multi-stage embolic device can include a cover element disposed over the first and/or second embolic devices.
These and other objects, along with advantages and features of the embodiments of the present invention herein disclosed, will become more apparent through reference to the following description, the accompanying drawings, and the claims. Furthermore, it is to be understood that the features of the various embodiments described herein are not mutually exclusive and can exist in various combinations and permutations.
In the drawings, like reference characters generally refer to the same parts throughout the different views. Also, the drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the invention. In the following description, various embodiments of the present invention are described with reference to the following drawings, in which:
Embodiments of the present invention are directed toward an improved design for an embolic device and methods of using the improved device. Neck blockage is an important function for embolic devices because it determines how much fluid can pass through the embolic device into the aneurysm, which can directly impact how effective the embolic device is in treating the vascular disorder. Embodiments of the present invention include embolic devices having shapes and/or configurations that accomplish improved neck blockage and other performance parameters over conventional devices.
In general, all of the embolic devices described herein can take any known form, e.g., a microcoil (e.g., bare platinum coil), flat sheet, thin film, combinations thereof, etc., even though in some instances a particular device may only be described herein as having one of these forms. In addition, all of the embolic devices described herein can be formed from any suitable material, e.g., shape memory material (e.g., nitinol), platinum, combinations thereof, etc., even though in some instances a particular device may only be described herein as being formed of one of these materials. Furthermore, in various instances, all of the embolic devices described herein can include a structure (e.g., microcoil, flat sheet, thin film, etc.) covered by a cover element, as described for example in U.S. Patent Publication No. US-2016-0022275-A1, which is incorporated herein by reference in its entirety.
In various embodiments of the invention, an embolic device is formed from a structure. As shown for example in
As shown in
One problem experienced with conventional devices is that their effectiveness in blocking an aneurysm neck is significantly affected by the orientation of the device upon delivery to a treatment site, which can sometimes be difficult to accomplish in a repeatable manner. Embodiments of the present invention solve this problem by featuring an embolic device that effectively blocks the aneurysm neck 106 regardless of its orientation upon placement into the aneurysm 104 or, in some cases, that blocks the aneurysm neck 106 in many more orientations than a conventional device (e.g., the majority of the orientations).
One example of a device that blocks the aneurysm neck 106 in a majority (or, in some cases, all) orientations is the embolic device 300 shown in
Example dimensions of the embolic device 300 are shown in
In various embodiments, embolic devices of the present invention can be formed from a flat sheet (e.g., formed from nitinol). In general, the flat sheet can be formed into any suitable shape. For example,
In various embodiments, as shown in
In various embodiments, an embolic device 700 can include alternating narrow portions 702 and link portions 704, as shown for example in
In some instances, as shown for example in
In various embodiments, the embolic devices described herein can be introduced, delivered, positioned, and implanted within a vascular disorder using a microcatheter. The microcatheter can be a flexible, small diameter catheter having, for example, an inside diameter between 0.015 inches and 0.035 inches (e.g., between 0.016 inches and 0.021 inches). The microcatheter may be introduced by an introducer sheath/guiding catheter combination placed in the femoral artery or groin area of a patient. In some instances, the microcatheter is guided into the vascular disorder with guidewires (e.g., long, torqueable proximal wire sections with more flexible distal wire sections designed to be advanced within tortuous vessels). Such guidewires may be visible using fluoroscopy and may be used to first access the vascular disorder, thereby allowing the microcatheter to be advanced over it into the disorder.
In some instances, once the tip of the microcatheter has accessed the vascular disorder, the guidewire is removed from the catheter lumen. The embolic device may then be placed into the proximal open end of the microcatheter and advanced through the microcatheter with a delivery mechanism. The embolic device may attach to a delivery mechanism via any suitable structure, e.g., a loop 706 (
Further explanation regarding the shape of the embolic devices described herein at various stages of the delivery process is instructive. The embolic device are generally manufactured to have a particular shape in an unconstrained configuration, e.g., as the device would exist in packaging or an operating room before being delivered to a patient. The particular shape can include any of the embolic device shapes described herein. During delivery, the embolic device is straightened out so that it can fit within and be delivered through a microcatheter (as described above). Once deployed out of the microcatheter to the vascular disorder, the embolic device can reform the shape it was manufactured to have (e.g., aided by a shape memory material). However, in some instances, the embolic device may not reform exactly into the shape it was manufactured to have, based on constraints imposed by the vascular disorder and other surrounding structures.
In various embodiments, the link portions 704 of the embolic device 700 shown in
In various embodiments, the aneurysm 104 can be treated by an embolic device shaped to form at least one infinity shape portion, as shown for example in
In various embodiments, multiple embolic devices can be joined with an interconnect element. The inventors have identified that when the portion of the device that fills the interior of the aneurysm cavity moves (e.g., to expand into apposition with an interior wall of the cavity) it can cause the portion of the device blocking the aneurysm neck to also move or shift, which can impact the effectiveness of the device in blocking the neck.
As a solution to this and other problems, embodiments of the present invention include a multi-stage embolic device that includes at least two embolic devices joined by an interconnect element that permits independent freedom of motion and/or relative positioning of each embolic device while they remain joined together. As shown for example in
In general, an interconnect element 1006 joins the embolic devices 1002, 1004 and can include any structure that permits independent freedom of motion and/or relative positioning of each embolic device while they remain joined together. As used herein, independent freedom of motion means that the only constraint on the motion between the embolic devices is that they remain coupled. In various instances, any movement about a coupling point is possible. As a result, motion of the second embolic device 1004 within the aneurysm cavity does not necessarily result in a corresponding motion of the first embolic device 1002 blocking the neck of the aneurysm. In some instances, permitting this freedom of motion represents an advantage of using an interconnect element to join two embolic devices, as opposed to using separate portions of a single coil (or other device) of unitary construction. While the separate portions of a single coil (or other device) may have some independence, they are generally more constrained due to the manufacturing realities of manufacturing a coil (or other device) of unitary construction. In contrast, in some instances, joining two different embolic devices with an interconnect element can afford much greater freedom of motion between the devices. In general, the interconnect element 1006 can be located at any location within or around the aneurysm, depending on where it is advantageous to have independent freedom of motion between the devices, not just the location shown in
As a few non-limiting examples, the interconnect element can include two linked loops, a nitinol coil (in some cases covering another interconnect element, and in other cases by itself), a hook and loop scheme, a hinge, a suture element, a hole and loop, a ball and socket scheme, a pivot joint, a ball and pivot joint, a universal joint, a saddle joint, any mechanical articulating joint with one or more degrees of freedom, or combinations thereof. In some instances, the interconnect element 1006 can be formed from certain portions of the first embolic device 1002 and the second embolic device 1004. For example, one component of the interconnect element 1006 can be a loop formed at a distal or proximal end of the first embolic device 1002 (e.g., of unitary construction or integral with the first embolic device 1002) and another component of the interconnect element 1006 can be a loop formed at a distal or proximal end of the second embolic device 1004 (e.g., of unitary construction or integral with the second embolic device 1004). In other instances, the interconnect element 1006 is not of unitary construction or integral with either the first embolic device 1002 or the second embolic device 1004 (i.e., the interconnect element is of non-unitary construction or of non-monolithic construction or non-integral with each of the first and second embolic devices 1002, 1004) and is, instead, fastened, adhered, and/or attached to the first and second embolic devices 1002, 1004. In other instances, the interconnect element 1006 is of unitary construction or integral with one of the first and second embolic devices 1002, 1004, and of non-unitary construction or of non-monolithic construction or non-integral with the other embolic device. In various embodiments, regardless of the particular structure employed, two of the first embolic device 1002, the second embolic device 1004, and the interconnect element 1006 are of non-unitary construction with each other.
In various embodiments, more than two embolic devices can be joined together, for example, in parallel using more than one interconnect element. Alternatively, more than two embolic devices can be joined together in series using more than one interconnect element (e.g., up to one less than the number of embolic devices). Combinations of series and parallel arrangements are also contemplated. In general, any number of embolic devices can be joined, e.g., 2, 3, 4, 5, 10, etc. As shown in
In various embodiments, each of the embolic devices (e.g., 1002, 1004, 1008) of the multi-stage embolic device 1000 can have different properties and behave differently from each other. In general, any embolic device property can be variable amongst the embolic devices. For example, some or all of the embolic devices can have different sizes, shapes, lengths, stiffness, porosity, etc. In other instances, some of all of the embolic devices can have the same of some or all properties. This customizable and independent nature of the embolic device properties can enable operators (e.g., physicians) greater freedom to shape and control coil deployment and positioning than with conventional devices. As one example, an operator can deliver a coil such that it is initially positioned in a first direction and then pivots to be positioned in a different direction at an angle (e.g., 15°, 30°, 45°, 60°, 75°, 90°, etc.) to the first direction.
As mentioned above, in various embodiments, the embolic devices described herein can include a structure (e.g., microcoil, flat sheet, thin film, etc.) covered by a cover element or not covered by a cover element. With reference to the multi-stage embolic device 1000, in various embodiments, any, none, or all of the individual embolic devices (e.g., 1002, 1004, 1008, etc.) can be covered or not covered by a cover element.
Unless expressly described elsewhere in this application (e.g., the use of the word “substantially” with respect to a geometric shape), as used herein, when the term “substantially” or “about” is before a quantitative value, the present disclosure also includes the specific quantitative value itself, as well as a ±10% variation from the nominal value unless otherwise indicated or inferred.
Having described certain embodiments of the invention, it will be apparent to those of ordinary skill in the art that other embodiments incorporating the concepts disclosed herein may be used without departing from the spirit and scope of the invention. Accordingly, the described embodiments are to be considered in all respects as only illustrative and not restrictive.
Claims
1. An embolic device for use in treating a vascular disorder, the embolic device comprising:
- a flexible structure comprising a series of alternating narrow portions and link portions, each link portion circumscribing an opening in at least one plane,
- wherein the structure is adapted to form a spiral shape when unconstrained.
2. The embolic device of claim 1, wherein the structure comprises at least one of a coil, a flat sheet, a thin film, and combinations thereof.
3. The embolic device of claim 1, wherein the structure comprises a material selected from the group consisting of platinum, nitinol, alloys thereof, and combinations thereof.
4. The embolic device of claim 1, wherein the structure comprises a thickness in a range from 0.0005 inches to 0.027 inches.
5. The embolic device of claim 1, wherein each narrow portion comprises a helically wound coil and each link portion comprises at least one of a flat sheet and a thin film.
6. The embolic device of claim 1, wherein at least a portion of the embolic device is radiopaque.
7. The embolic device of claim 1, wherein each narrow portion is fixedly attached to proximate link portions and further comprising:
- a strain relief element between each narrow portion and the proximate link portions.
8. The embolic device of claim 7, wherein the strain relief element is formed from at least one of a melted suture material and a melted polymer.
9. The embolic device of claim 1, wherein each link portion comprises a diamond-like shape.
10. The embolic device of claim 1, wherein each link portion is adapted to compress when the embolic device is disposed within a microcatheter.
11. The embolic device of claim 10, wherein each link portion is further adapted to expand upon the deployment of the embolic device from the microcatheter.
12. The embolic device of claim 1, wherein the narrow portions and the link portions alternate with consistent spacing.
13. The embolic device of claim 1, wherein the narrow portions and the link portions alternate with inconsistent spacing.
14. The embolic device of claim 1, further comprising a cover element disposed over the structure.
15. The embolic device of claim 1, further comprising an interconnect element disposed at an end of the embolic device for attaching the embolic device to one or more different embolic devices.
16. The embolic device of claim 15, wherein the embolic device and the one or more different embolic devices are attached in series.
17. An embolic device for use in treating a vascular disorder, the embolic device comprising:
- a flexible structure adapted to form at least one infinity shape portion when unconstrained, wherein the infinity shape portion comprises two adjacent loops crossing at a single point.
18. The embolic device of claim 17, wherein the structure comprises at least one of a coil, a flat sheet, a thin film, and combinations thereof.
19. The embolic device of claim 17, wherein the structure comprises a material selected from the group consisting of platinum, nitinol, alloys thereof, and combinations thereof.
20.-27. (canceled)
28. A multi-stage embolic device for use in treating a vascular disorder, the multi-stage embolic device comprising:
- a first embolic device;
- a second embolic device different from the first embolic device; and
- an interconnect element joining the first and second embolic devices permitting independent freedom of motion between the first and second embolic devices while remaining joined together.
29.-46. (canceled)
Type: Application
Filed: Apr 4, 2019
Publication Date: Oct 10, 2019
Patent Grant number: 11819215
Inventors: Amiel R. Aguilar (San Jose, CA), Crystal K. Sein-Lwin (Hayward, CA), Nga Doan (San Jose, CA), Regina C. Velasco (Fremont, CA)
Application Number: 16/375,516